Version 1.7.0 released

New features:

• twister.trk
• Bridge object.
• Fade out flash transition.
• Turn left and turn right signs.
• CLI option to force vsync off.
• New crash sound.
• Editor: visualize computer hints.
• Move user tracks to the beginning of the track array.
• Increase the initial slide friction to 1.0

Bug fixes:

• Don't show prev/next if on first/last item.
• Remove specular shaders from crate and tire.
• Fix computer driving line in curvastone.trk
• Fix off-track detection on 'sand grass straight' tile.

Other:

• Small improvements to render timing.
• Optimize VBO, VAO and texture binding.
• Optimize viewport switching.
• Optimize the use of GL_DEPTH_TEST.
• Use random functionality from C++11.
• Improve sky reflection.
• Update scripts/genericLinuxBuildQt5